Hi. I posted a while ago in this thread. My Mac had been freezing every day since I'd upgraded from Lion. I may be writing too soon, but my Mac has not frozen in three days.
I called Apple at the end of last week to tell them that the freezing was still happening with 10.8.1 and I lucked out and got a woman who is supposedly higher up than the normal tech person.
She emailed a program to me that extracts all the info on my Mac regarding the crashes. I then emailed the data back to her. She said maybe the freezing was partially due to something else not working -- maybe something that might have been corrupted previous to upgrading to Mountain Lion. She's been trying to troubleshoot what that might be. She called me on Monday and she's going to call me again on Friday. It's really the best tech support I've ever gotten, and it's kind of ridiculous considering Mountain Lion cost $19.99. (My Mac's warrantly expired in 2010). It's another reason I'm glad I bought a Mac.
Anyway, she noticed that my Lexmark printer software was going nuts. Apparently, there are some Lexmark processes going on in the background even when the printer isn't in use. She said the extracted info showed that the Lexmark software was constantly quitting and restarting. I tried seeing this activity myself in Activity Monitor, but Activity Monitor doesn't seem to show it.
So, my Mac has not frozen for three days and I've been using it regularly. But, I realized that I haven't had my printer connected to my Mac during that time. Maybe that's just a coincidence and if my Mac does freeze while the printer is disconnected, then I'll post again on here to let people know. But this is the longest period of time I've gone without freezes since I installed Mountain Lion. If it still hasn't frozen in a few days then I'm going to plug in my printer and see what happens.
If you have a Lexmark printer too, you may want to disconnect it and see what happens. Mine is an all-in-one, the S505, which I think is from 2009.